The present invention generally relates to an improvement in apparatuses installed in ink jet printers for collecting an ink mist which is entailed by impingement of an ink droplet ejected from an ink jet head onto a paper sheet. More particularly, the present invention is concerned with an improvement in an ink mist collection apparatus of the type which employs an ink mist adsorptive member interposed between the paper sheet and the ink jet head.
In an ink jet printer, it is known that an ink droplet issued from an ink jet head is partly scattered to form an ink mist when it impinges on a paper sheet. The ink mist tends to be deposited on the paper sheet to smear it and/or stick to deflection electrodes to cause a leak thereacross, degrading the reproduction of desired information.
Some implements have hitherto been proposed to settle such a problem originating from ink mists. An ink mist collector is known which comprises an ink mist adsorptive member disposed between a paper sheet and deflection electrodes such that it adsorbs ink mists formed by ink droplets. A drawback inherent in this type of ink mist collector lies in the limited adsorption capacity which makes a long time of use of such a collector difficult. Another prior art ink mist collector is designed for a prolonged time of service and, for this purpose, it uses a double-layer adsorptive member between a paper sheet and deflection electrodes. Despite such an effort to increase the adsorption capacity, the limited available spacing between the paper sheet and the deflection electrodes still prevents the adsorptive member from having a sufficient volume. A farther prior art ink mist collector relies on a pump or like means for forced collection of ink mists. Though positive in nature, this type of mist collector suffers from an increase in cost due to the use of a pump or like forcible collection means.
In the adsorption type mist collectors, the adsorptive member protrudes toward a paper sheet beyond the front end of the ink jet head. When a paper sheet is inserted into the printer, its leading end will contact the adsorptive member to be thereby smeared. Likewise, a computer format sheet or like folded sheet will be smeared by the adsorptive member along its folds.
Furthermore, the ink mist adsorptive member in such a prior art collector is securely mounted inside a head cover by screws or the like to a carriage which has a head, electrodes and others mounted thereon. To replace the adsorptive member, therefore, one has to remove the head cover and then loosen the screws to remove the adsorptive member. Meanwhile, since the degree of contamination of the adsorptive member is not visible from outside the head cover, an appropriate timing for the replacement of the adsorptive member cannot be known.